Alt-C not working in Blender 2.8
The shortcut Alt+c was removed from the default keymap in 2.80 unfortunately. You can bring it back by just right-clicking on the option in the menu and selecting Assign Shortcut. If you do that you will have a shortcut for the specific operation and not the convert menu like it was in previous versions. If you wanted to bring it back exactly like it was, you need to go to the User Preferences(F4 -> p), find it using Key-Binding search mode and just remove the Target property there so it is unset and you are presented with the choice when you hit the hotkey.